import html2Canvas from 'html2canvas'
import JsPDF from 'jspdf'
export default{
 install (Vue, options) {
 Vue.prototype.getPdf = function (papertitle) {
  var title = papertitle
  this.$modal
        .confirm('是否导出标题为"' + papertitle + '"的问卷？')
        .then(() => {
            html2Canvas(document.querySelector('#pdfDom'), {
                allowTaint: true
                }).then(function (canvas) {
                let contentWidth = canvas.width
                let contentHeight = canvas.height
                let pageHeight = contentWidth / 592.28 * 841.89
                let leftHeight = contentHeight
                let position = 0
                let imgWidth = 595.28
                let imgHeight = 592.28 / contentWidth * contentHeight
                let pageData = canvas.toDataURL('image/jpeg', 1.0)
                let PDF = new JsPDF('', 'pt', 'a4')
                if (leftHeight < pageHeight) {
                 PDF.addImage(pageData, 'JPEG', 0, 0, imgWidth, imgHeight)
                } else {
                 while (leftHeight > 0) {
                 PDF.addImage(pageData, 'JPEG', 0, position, imgWidth, imgHeight)
                 leftHeight -= pageHeight
                 position -= 841.89
                 if (leftHeight > 0) {
                  PDF.addPage()
                 }
                 }
                }
                PDF.save(title + '.pdf')
                }
                )
            this.$modal.msgSuccess("导出问卷成功！");
          })
          .catch(() => {});
  
 }
 }
}